Error using sum.Invalid data type. First argument must be numeric or logical.

I want to calculate the mean value but its cannot calculate that and giving error.

%%%%%%%%%%%%%%%%error%%%%%%%%%%%%%

Error using sum

Invalid data type. First argument must be numeric or logical.

Error in mean (line 116)

y = sum(x, dim, flag) ./ size(x,dim);

Error in featureNormalize (line 7)

mu = mean (X);

Error in trynsl (line 14)

X_n = featureNormalize(X);

%%%%functioncode%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function[X_norm,mu,sigma] = featureNormalize(X)
       X_norm = X;
       mu = zeros(1, size(X, 2));
       sigma = zeros(1, size(X, 2));
        mu = mean (X);
        for i=1:size(X, 2)
        X(:,i) = X(:,i) - mu(i);
        end
        sigma = std (X);
        for i=1:size(X, 2)
        X(:,i) = X(:,i) ./ sigma(i);
        end
        X_norm = X;
  end

[Walter Roberson]

What is class(X) ?

I predict that X is a cell array.

[Mavra Mehmood]

this the code in which i call that function.X was cell array but further i convrt it into table.

%%%%%%%%Code%%%%%%%%%%
fid = fopen('KDDTrain+.txt','r');
data = textscan(fid,repmat('%s',1,43),'delimiter',',','CollectOutput',true);
data = data{1};
fclose(fid);
data(:,1) = num2cell(str2double(data(:,1)) );
data(:,5:41) = num2cell(str2double(data(:,5:41)) );
data(:,43) = num2cell(str2double(data(:,43)) );
%X = cell2mat(data); % convert cell to matrix
X= cell2table(data);
% Before normalization separate the output from the file
y = X(:,42);
X(:,42) = [ ];
X_n = featureNormalize(X);
%If there is any column with NaN values, remove it
X_n = X_n(:,all(~isnan(X_n)));
X_n = [ones(length(X_n), 1) X_n]; %add a new column with 1's

[Walter Roberson]

X_n = featureNormalize(X{:,:});

[Mavra Mehmood]

Thankyou for your help now it's given this error

at doing this %% X_n = featureNormalize(X{:,:});

Error using trynsl (line 15)

Unable to concatenate the table variables 'data1' and 'data2', because their types are double and cell

[Walter Roberson]

Your columns 2, 3, and 4 are character vectors. You cannot normalize character vectors.

Note that your y is a table that contains a single variable that is character vectors.

Note by the way that you can do things like,

fmt_cell = repmat({'%d'}, 1, 43);
fmt_cell([2:4, 42]) = {'%s'};
fmt = [fmt_cell{:}];
data = textscan(fid,fmt,'delimiter',',','CollectOutput',true);
d1 = data{1};    %numeric
d2_4 = data{2};  %character
d5_41 = data{3}; %numeric
y = data{4};     %character
d43 = data{5};
X = [d1, d5_41, d43];
X_n = featureNormalize(X);

[Mavra Mehmood]

it stills not working properly

Error in featureNormalize (line 12)

sigma = std (X);

Error in trynsl (line 25)

X_n = featureNormalize(X);

code

function[X_norm,mu,sigma] = featureNormalize(X)

X_norm = X;

mu = zeros(1, size(X, 2));

sigma = zeros(1, size(X, 2));

mu = mean (X);

for i=1:size(X, 2)

X(:,i) = X(:,i) - mu(i);

end

sigma = std(X);

for i=1:size(X, 2)

X(:,i) = X(:,i) ./ sigma(i);

end

X_norm = X;

end